We had a bug party for my sons 3rd birthday and it was a huge hit. Made a caterpillar cake out of cupcakes for the kids and also a large cake with plastic bugs all over it for the adults. I made a large ladybug poster with no spots.  I cut out spots and threw them all over the yard and the kids went and found them. When they found them, they got to put them on the ladybug. We made wooden bug boxes with little hinged doors and screened covers and painted them with one for each child and their name on it. It was some work but fun - you could buy them and paint the name on instead. The biggest hit was the bug catching part of the party.  We got all the kids in the front yard with their bug catching houses.  My husband and I then released about 1500 ladybugs and 500 crickets and the kids scrambled to catch them!  I got the ladybugs at a garden store and the crickets at a pet store. Everyone took their bugs home and released them later that week - after enjoying cricket noises to go to sleep to!